The prior-art setup folding machines with enclosure feed mechanisms are each equipped with two folding pockets and are adjusted such that they produce an inwardly curled fold. The paper deflectors otherwise common in setup folding machines, with which the intake openings of the two folding pockets can be closed and the material being folded is guided past one folding pocket and to the next folding station, are not present in such setup folding machines equipped with enclosure feed mechanisms. They are not needed, because only the inwardly curled fold type with two folds is used.
On the other hand, it is only possible to add enclosures to the first fold of the material being folded, because direct deflection of the material being folded from the first folding station into the second folding station is not possible because of the absence of a paper deflector. Moreover, such setup folding machines can be provided with only one enclosure feed mechanism, which is directed directly toward the first folding station, which means that only one enclosure can be added to one sheet of material to be folded.
A pocketless paper folding machine is known from Germany patent DE 38,30,656 C1. It discloses a contactless feed limiting device is located in a feed web of the material to be folded which passes by a folding station. The feed limiting device determines the actual folding length, and can be actuated individually for each folding process by means of a microprocessor and an electronic control device. The respective material being folded is deflected toward the folding stations by knife-like or bar-like deflecting members at a speed corresponding to the feed movement of the material being folded. However, this prior-art paper folding machine is not provided with an enclosure feed mechanism.
In addition, a folding machine equipped with two folding stations and two folding pockets is known from German publication DE 38,40,856 A1. It discloses a sheet guiding member driven by a linear motor and controlled by an electronic control device arranged between the first and second folding stations. This folding machine also has no enclosure feed mechanism, so that the sheet guiding member is used only to determine the type of folding.